The present invention relates to an apparatus for treating various waste oils and in particular to an apparatus for treating various waste oils containing a large percentage of water.
One of the recent worldwide problems is environmental pollution particularly in rivers and seas. Waste oils often pollute the rivers and seas. Such waste oils are produced in various places, for example, as waste liquids from houses in daily life and ships. The waste oils are apt to contain a lot of water.
Japanese Patent Unexamined Publication No. 48-73830, Japanese Utility Model Unexamined Publication No. 51-76179 and Japanese Utility Model Examined Publication No. 52-383 disclose that waste oils are first separated from water and then treated by burning. In the prior art apparatuses disclosed in such documents, waste oil mixed with water is fed into a water-oil separation means where water is separated from oil due to different specific gravities thereof after heated.
However, any waste oil containing a large percentage of water cannot be burned before they are separated from each other according to the prior art apparatuses. In order that a lot of waste oil mixed with water is treated to 5 ppm, for instance, a large sized oil-water separation apparatus must be used to separate the oil from the water. Therefore, treatment efficiency is low. For example, it is difficult to separate the oil from the water to such a degree that the water can be discharged, in particular in case of emulsion oil. Also, treatment costs are high.
On the other hand, waste oil containing a small percentage of water can be burned, but smell and/or smoke problems take place as secondary pollutions, particulary in case of heavy oil C or pilge oil.